Tutorial: Advanced Isolation
Did you really think I got four exceptionally well trained giraffes to pose calmly in my super-sized snow-white studio with a hundred gigantic light boxes? Na-hah! Actually, I got them in their natural habitat amidst a peaceful green-filled landscape (rollover the image to see for yourself!). And then I put my photoshop hat on and went to work. The end result is much more fun and much more useful to designers.
The first step of this isolation involves what I covered in the first part of this Isolation Tutorial: you have to remove as much of this landscap-y background as possible before you get to the hard part - working around hair and making sure all the fine hair detail in around giraffe bodies and tails is preserved. Here, I will show you a couple of tricks that should come in handy. But first, you have to remove the surrounding landscape, as much as you can. Again, you can use any of the strategies I covered in part I. To sum them up:
Given the complexity of the background landscape and given the complexity of my main subject, the pen tool is my first choice for tracing around the giraffes. Other options would offer you a lot less precision and would be a lot more time-consuming if you'd want to get as much of the background removed (might still be a good choice if yo are versatile with a digital tablet). In any case, I went with the pen tool and started my trace, trying to curve around the animals as accuratly as I could (rollover the image to see a bigger version). Theoretically, you want to make your selection with the pen tool (remember, whenever you trace your objects with the pen tool you must do it at least at 100% zoom, I usually zoom to 200-300% depending on the surface), close it, feather it, isolate it from the background. I used 2px feathering for this part of the image, which I will use in the rest of this tutorial. As you can see, I did a fairly good job tracing the giraffes, but there is still a lot of background left. Let's tackle the fur first, and leave the tail for dessert.
You have three strategies (I am sure there are more, but here I'll focus on these three) for perfecting your isolation and making fur look credible and well isolated from the background.
The logic behind the "pulling" strategy is that you remove all the background and a little bit of the fur as well, and then you "pull" the fur. This may sound a little confusing, so let me illustrate it. First, you have to select a small round soft brush, set its color to "white" (the color of our desired background), and paint over both the background AND a little bit of the fur. Step-by-step:
(1) Select your brush tool, make sure it's set to white
(2) Stroke over both the leftovers of the background while covering over a little bit of the fur (3). Make sure the brush is soft, then you would get a smooth transition between the fur and the white of the background. Unfortunately, it still doesn't look like animal fur.
Now, it's time for smudging. The pulling strategy implies literally what its name stands for: you grab the "fur" and pull strands of fur outwards. To do this you need to use the "smudge" tool to grab the color of the fur and smudge it out into the area of the white background. Again, this is something that's easier illustrated than explained in words: First, select the "smudge" tool, right click your mouse and set its size to something small, say 5px. The size of the selection would depend on the size of your image. Visually, the size of your smudge tool should be about the same as the size of a small strand of fur.
As the image on the left illustrates, smudging is similar to the logic of drawing straight lines using the "shift" trick.
First, click on the area of the fur somewhere near the edge, after that press the "shift" key and hold it down1
Second, click on the background area, on the white, not too far from the fur (remember, you are still holding the shift key down). Another way to "smudge" (or to pull) is merely to move your mouse in the direction of where you want the stroke to follow (so, instead of clicking, holding shift down, clicking again you click, hold your left mouse key down and move the mouose in the direction of the stroke) See the stroke?????
Numbers (3), (4) and (5) illustrate three different degrees of "strength" of your smudge tool. #3 is smudge tool set at 100% strength, as you see there is absolutely no fading away towards the end of your stroke, and the stroke is full length from point (1) to point (2). #4 is smudge tool set at 75% strength, and is shorter in length. #5 is smudge tool set at 50% strength and it's even shorter (the strength window is usually in the top left panel of the photoshop window). So, you get the idea? After a few hundred strokes, with varying degrees of smudge strength and direction, you should be getting something like the example on the right. Now, all you have to do is keep going :) :) After a few thousand strokes, you are done :) (In a later tutorial I'll show you how you can create brushes to simplify this task down to a lot fewer strokes)
All right, another way to achieve the same result is by "painting" strokes of white into your fur. The logic is the same: use a small soft brush to erase all of the background and a little bit of the fur (just to make sure there 's no background creeping in between stray hairs). In contrast to "pulling", you are using the smudge tool to paint a little bit of the white background into the fur. The same kind of effect can be achieved by painting with a white brush with 50-75% (or lower) opacity. Keep "painting" with the smudge tool dipped in white towards the fur until you are satisfied with your result. With practice, you'll learn to recognize whether pulling or painting creates a more realistic effect. Generally, for fluffier and poofier animals/surfaces I use smudging and for smoother surfaces/shorthaired animals, the painting trick works better. Now, using a combination of erasing, smudging and dodging you should easily "take care" of any kind of fur, human hair or animal tails :)
Now, on to dodging. Dodging is most effective when you have a light, monotone background. The background could be any color, as long as it's light. Let me use a different example to illustrate dodging. Meet Daisy, a member of the ChasingMoments family (This is not a really bad studio image, by the way, this is a snapshot of Daisy I took while she was cozying up on the bed: read, relatively poor room lighting, yellow-ish background). You can use dodging whenever you want to create animal isolations over white, but you don't have enough light to knock out the background completely. Magic wand wouldn't tackle such a complex contour as fur; erasing and painting (or pulling and smudging) would be extremely time consuming compared to an easier strategy offered by dodging. But first, let me do some color correction: Daisy is under exposed, and the white balance is off. Using a combination of levels and brightenss, I made the image a bit lighter and fixed some of the color cast. Now, of course, let's create a duplicate, working level (this should become a habit of yours - always work on a duplicate level!).
Time for dodging. Select the dodge tool from the tools palette, set it to "highlights" (it's this setting that does most of the work and separates the light background from the dark foreground), set exposure to an intermediate value, in my case, I set it to 50%, although anything from 25 to 100% would work (the lower the exposure value, the more times you would have to stroke over the same area to convert the background color into white). In the example to the right you can see what kind of effect stroking with a dodge tool over a light background works.
Keep dodging until all of your background is white. For keeping the fur's poofy look I selected a very large soft brush (250-300px) and only brushed its edge around the cats's fur. I also switched to "sponge" tool to get rid of the leftovers of the yellow color cast around fur edges and did some more color adjustments. And voila. Here's the final result: quick and easy, but works only for certain kinds of isolations. I personally frequently use the "dodge" trick to whiten small details of the background as a finishing touch, after I've done all the isolation work. For example in this christmas ornament isolation, I dodged around the fine fir edges: the "highlight" option of the dodging tool does not alter the original color (the green of the fir), but burns out the surrounding color to white.